Some maintenance schedules use mileage, some use time, and many use both. When the manufacturer gives two triggers, the source document determines how they work together.
Parts wear from use, and materials age whether or not the vehicle moves. Oil oxidises, rubber hardens, brake fluid takes up moisture, and a battery loses capacity while parked. A distance figure captures the first effect and a time figure captures the second, so most schedules carry both.
It means the item is due as soon as either trigger is reached, not when both are. A service listed at a distance or a number of months arrives at the month figure for a car driven lightly, and at the distance figure for one driven hard. The order is not a choice made by the owner, it is written into the manufacturer schedule.
A vehicle that covers little distance still moves through its schedule on the clock. Owners in this position often find that the time trigger governs almost every item, and that the vehicle reaches service points with a low odometer reading. Entering the date the vehicle entered service, alongside distance, is what makes the resulting schedule correct for this case.
At the other end, a vehicle covering long distances reaches distance triggers repeatedly between time limits. Here the distance figure governs, and time-only items still arrive on their own schedule regardless of how many distance checkpoints have passed.
Not every entry has a pair. Some items are listed by distance alone, some by time alone. MaintenanceSpec records each item the way the source states it rather than filling in a missing trigger, so an item with no time limit is not given one.
Enter your distance and the date the vehicle entered service to see which trigger governs each item on your schedule.
Find my vehicleAnswers that apply generally. Timing for a specific car comes from its own schedule.
